Stucco News

Question and answers on Stucco and Plastering
-- January, 2013


I found your email online, and I was hoping you could answer a couple of
 quick stucco questions for me to help ease my mind.
 
1. We put on our finish/texture coat of stucco yesterday  around 4-5pm. The
day was overcast. Around 11pm-12midnight that same day it began to rain
 fairly hard for about 30minutes. The stucco was on the side of the house
 covered by roofing eaves/fascia boards, but I'm sure some water hit the
 stucco. Do you think this will damage the stucco at all? The texture looks
fine for now, but I'm worried that this will hurt the work somewhere down
 the road.
 
2. When would be a good time to paint this new stucco? How long must one
 wait for the stucco to dry before painting? Is primer needed for new stucco ?

 Thanks, I look forward to hearing back from you!

After mortar has set up for 7 hours, you should be able to take a fire hose to it, and not cause any damage, EXCEPT in cold weather. In cold weather the finish takes maybe 3 days or so to set up all
the way. If it rains in the meantime, the color can get messed up, but not the texture. It this case,
it 
doesn't matter, because the wall gets painted anyway.

We do have a magic solution for fixing the color, check out the next question.

The stucco should set up 30 days before painting, unless you are in a real pinch.
By painting the stucco you are sealing the pores, and interfering with the curing process.
Painting the stucco before 30 days, the mortar would never reach maximum strength.
Sure, it only has to be so strong, but by painting the stucco very prematurely, say in less than
2 weeks, you risk having paint peeling in the future because the stucco has too much of a
water content.

The best paint to use on new stucco is masonry paint and masonry primer.
 
I wrote that elastomeric paint was the best back in 1999 when I started my FAQ page.
I changed my mind and opinion since then all the information is pretty much obsolete.
I don't plan to edit the page because it is still way up there in the search engines and
directs people here.